Horton

Re: Non-reserved replication slots and slot advancing

Alvaro Herrera <alvherre@2ndquadrant.com>

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From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Andres Freund <andres@anarazel.de>
Cc: Michael Paquier <michael@paquier.xyz>, Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, pgsql-hackers@postgresql.org, petr@2ndquadrant.com, simon@2ndQuadrant.com
Date: 2018-07-09T18:48:28Z
Lists: pgsql-hackers 
On 2018-Jul-09, Andres Freund wrote:

> On 2018-07-09 15:48:33 +0900, Michael Paquier wrote:

> > +	if (XLogRecPtrIsInvalid(MyReplicationSlot->data.restart_lsn))
> > +	{
> > +		ReplicationSlotRelease();
> > +		ereport(ERROR,
> > +				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
> > +				 errmsg("cannot move slot not reserving WAL")));
> > +	}
> > +
> 
> I don't like this error message. It's unclear what refers to exactly
> what.  Nor is "move" a terminology used otherwise.  How about:
> "cannot advance replication slot that has not previously reserved WAL"
> or something similar?
> 
> Also, ERRCODE_FEATURE_NOT_SUPPORTED doesn't quite seem right. How about
> ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE?

+1 to both of Andres' suggestions.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Block replication slot advance for these not yet reserving WAL